The invention relates to a suction cleaning apparatus comprising a dirt collection container which has a suction inlet and is fluidly connected to at least one suction unit via at least one filter and at least one suction channel, and comprising at least one external air inlet which opens out into the suction channel downstream of the at least one filter and is selectively closable and openable by means of a closing body.
With such a suction cleaning apparatus, dirt and in an advantageous embodiment also liquid can be sucked up by applying negative pressure to the dirt collection container by means of the at least one suction unit, so that a suction flow is formed. The suction cleaning apparatus has at least one filter that is arranged in the flow path between the dirt collection container and the suction unit and serves to separate solid matter from the suction flow. During suction operation, dirt particles are increasingly deposited on the dirty side of the at least one filter facing towards the dirt collection container, so that the filter needs to be cleaned after a certain length of time. For the purpose of cleaning, external air can be applied to the clean side of the filter facing away from the dirt collection container by a closing body opening at least one external air inlet which opens out into the suction channel downstream of the filter.
Suction apparatuses of this type are, for example, known from DE 298 23 411 U1 and DE 10 2005 017 702 A1. Here the closing bodies are designed as a valve disk of a lift valve which can be held, by means of an electromagnet, in a closed position in which it closes the at least one external air inlet. When the supply of energy to the electromagnet is interrupted, the valve disk lifts off the external air inlet, so that external air can abruptly flow into the suction channel and impinge on the clean side of the filter. Suction cleaning apparatuses of this type have proved successful. However, in order for the filter cleaning process to function properly, the closing body designed as a valve disk of a lift valve requires considerable installation space.
It is an object of the present invention to improve a suction cleaning apparatus of the type indicated at the outset in such a manner that the installation space of the closing body required for proper filter cleaning can be reduced.